


Knot Expected

by halcyon1993



Series: The Kinky Adventures of a Wolf and His Boy [1]
Category: Teen Wolf (TV)
Genre: Alpha Derek Hale, Alpha/Beta/Omega Dynamics, Anal Fingering, Anal Sex, Breeding, Come Eating, Derek Hale is a Softie, Knotting, M/M, Marking, Mates Derek Hale/Stiles Stilinski, Mating Bites, Mating Cycles/In Heat, Mpreg, Multiple Orgasms, Omega Stiles Stilinski, Plot What Plot/Porn Without Plot, Possessive Sex, Rough Sex, Self-Lubrication, Unplanned Pregnancy
Language: English
Status: Completed
Published: 2017-11-13
Updated: 2017-11-13
Packaged: 2019-02-01 20:35:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,850
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12712476
Author URL: https://archiveofourown.org/users/halcyon1993/pseuds/halcyon1993
Summary: Stiles goes into an unexpected heat. His alpha takes care of him.





	Knot Expected

Stiles' day isn't going well.

He was cranky when he woke up, so much so that he snapped at Derek, his alpha, to leave him alone when he expressed concern. His skin feels tight and he has been unable to focus on any of his college classes. Now, in his last one before lunch, he feels like he is slowly cooking from the inside out. He doesn't remember ever feeling so overwhelmingly _hot_. It isn't even summer, hasn't been for months, and yet here he is, sitting in his Philosophy class and wishing someone would turn on the air conditioning and set it to high. He looks around the room to see if anyone else is experiencing the same thing, but no—he's the only one. Everyone else looks perfectly comfortable.

Stiles hates them.

Once the class has finished, he trudges wearily outside and meets Scott in the courtyard. When they're close, Scott frowns at him.

"Dude, are you okay?" the crooked-jawed beta asks. "You look weird."

"Well, aside from the fact that I'm _baking_ , yeah, I'm fine," Stiles grumbles. He pulls his notebook out of his backpack, tears out a few pages and uses them as a makeshift fan. The small breeze feels nice on his sweaty face. "Fuck, this day can't end soon enough."

"Do you wanna grab some pizza for lunch? Ali and—"

Stiles isn't listening. He stops walking, realisation sweeping over him.

"Stiles? What's wrong?!" Scott frets, catching the shock on Stiles' pale face. His hands hover but don't touch.

The back of Stiles' underwear is suddenly wet, a wave of slick seeping from his clenching hole. "Oh God..." Stiles whines, hunching over and shutting his eyes. He drops his backpack to the ground and wraps his arms around his abdomen, which suddenly throbs painfully. "No, no, this can't be happening. It's not supposed to happen!"

"Stiles, _what_? _What_ isn't supposed to happen?!" Scott exclaims.

"H-heat. M'in heat!"

"Oh." It takes a moment to sink in. "Oh! Shit, um...what do we do?"

"Derek," Stiles gasps. "I need to get to Derek."

Glancing around, Scott notes that they have an audience. As a beta, Stiles just smells like a regular person to him, but that isn't the case for others—Scott can see several alphas in the area eyeing his friend longingly, licking their lips. While he can't smell it himself, Scott knows that the scent of an omega in heat is a strong one, specially designed to catch the attention of a virile alpha to breed them. A fierce glare is thankfully enough to keep the alphas near them from making a move, but, aware of the fact that Stiles already being mated won't matter to some, he steels himself just in case he does have to block an unwanted advance.

Scott picks up Stiles' backpack, slings Stiles' right arm over his shoulders and helps him walk. "Alright, we'll get you to your Jeep, I'll call Derek, and we can meet him at your place," he expounds. "Sound like a plan?"

"Y-yeah..."

It's slow going. Stiles stumbles every so often, so Scott has to keep stopping to help him regain his footing. Mercifully, no one approaches them and eventually they make it to Stiles' sky-blue 4x4. Scott fumbles to open the passenger door and carefully helps the omega climb inside. Already Stiles' eyes are glassy and slightly unfocused and sweat drips off of him, signs that his heat is fast overtaking him. Scott knows Stiles hasn't had a heat in years thanks to suppressants, so when this one finally hits properly, it's going to hit _hard_.

They have to hurry.

Once he is in the driver's seat, Scott pulls out his phone and dials. "C'mon, c'mon...pick up," he murmurs as it rings.

 _"Scott?"_ comes Derek's tinny voice. _"What's going on? I'm working."_

"It's Stiles. He's in heat," Scott explains. He hears Derek inhale sharply. "I'm taking him home. Meet us there." Not waiting for a response, Scott hangs up his phone and looks at Stiles. The other boy has his forehead pressed to the cool glass of his window.

"You got your keys?" Scott asks.

"Mmm...here."

Stiles wrestles with his jeans pocket until the keyring falls out.

Scott snaps them up before they can fall between the seats. "Let's get you home."

* * *

When Scott pulls into the bungalow Stiles and Derek share, Derek is already waiting anxiously by his car. As soon as the Jeep comes to a stop, Stiles opens the passenger door and tries to get out, desperate to get to his alpha. But his heat makes him even more uncoordinated and he almost falls over. Derek saves him, rushing forward and pulling his mate into his arms before Stiles can accidentally injure himself. A viscous wet patch is left on the passenger seat.

Scott gets out, too, and locks up the Jeep. "You got him?"

Derek glances at the beta. "Yeah. You okay to get yourself back to class?"

Scott nods. "Don't worry about me. Just take care of him." He gestures to Stiles, who chooses that moment to bury his nose in Derek's neck with a pitiful sound. Derek's knees go weak but he doesn't fall.

"Thanks."

Derek turns away from Scott and walks up the front path. He kicks open the front door and steps inside the bungalow just as Stiles whines sadly.

"Derek..." the omega pants.

"Shh, I'm here. I've got you," Derek assures him quietly, burying his nose in his mate's hair and breathing him in. If he hadn't already been hard as a diamond from the moment he first touched Stiles outside, the pungent scent of his omega's heat would have him there in a heartbeat. "I'll take care of you." Derek heads into their bedroom and gently places Stiles on their king-size bed. "You okay to get yourself undressed? I need to get a few things ready."

Stiles nods tiredly and begins wrestling off his T-shirt, so Derek leaves the room. Now that he is alone and his mind isn't clouded so much by the alluring scent of his mate, he thinks frantically of everything he has ever learned about heats. He has never been around an omega in heat before; Stiles has never had one while they've been together. In fact, he doesn't think Stiles has had a heat since his first at fourteen. Ever since then he has been on suppressants. Why all of that has changed now is a mystery, because as far as he knew Stiles was still on the medication. But that's a problem to be tackled once everything is over.

In the kitchen, Derek opens the fridge and retrieves several bottles of water. At the rate Stiles will sweat, come and produce slick, he'll need extra hydration. Next, Derek retrieves an unopened box of energy bars from the cupboard. Both of them are going be expending a lot of energy over the coming days, so they will be important, too. His arms full, Derek heads back to the bedroom.

He finds Stiles struggling to get out of his chinos. "Let me," Derek offers.

He deposits the supplies on his nightstand and goes back to the foot of the bed. He guides Stiles to lie down on his back, then pops the button of Stiles' chinos through the placket and pulls down the zipper. With jerky movements, Derek yanks down his mate's underwear along with his chinos. He lets them fall from his grip and they hit the hardwood floor with a suspicious splat. Looking down, Derek discovers that the garments are soaked with slick. The sight makes his dick throb.

After a few moments, Derek shakes himself from his stupor and refocuses on Stiles. The omega is still reclined on the bed, his skin flushed and already shiny with sweat. His eyes are clenched shut in a frown and his breaths come short and fast. Stiles' sweet little omega cock is already red and raw and leaking copiously.

He's the hottest thing Derek has ever seen.

"Okay, let's get some fluids in you now to preempt things," he says. He picks up a bottle of water, twists off the cap and, after helping Stiles sit up again, holds the rim to his lips. Stiles drinks sluggishly and dribbles a bit, but he manages to down about half of the bottle before growing restless again. When the omega moves his head away, Derek puts the water back and helps Stiles further up the bed. He is shocked by the sheer heat of Stiles' naked skin. It's nearly burning, but he supposes that is to be expected.

The water helping to cool him down a bit, Stiles watches Derek through half-lidded eyes as he begins stripping out of his own clothes. There's a hunger in them with which Derek is intimately familiar. He has seen it directed at him many, many times over the course of their relationship and like always, it sends a thrill through his body to know that his mate finds him as attractive as he finds his mate.

He had expected Stiles to be nearly insensible by now, unable to focus on anything but his need for a knot, but clearly that isn't the case.

The situation making him feel like being a little saucier than usual, Derek decides to give his mate a little show while he has his rapturous attention. He grabs the hem of his black Henley, takes his time pulling it off over his head and imagines that, with each new piece of hirsute skin he reveals, Stiles' eyes burn hotter and hotter. When he pulls his head out of the head hole and the garment is discarded with Stiles' clothes on the floor, he finds that he wasn't far off—Stiles' irises now glow gold and run up and down Derek's naked torso with great appreciation.

Derek runs a hand down his front, fingers carding through the dark hairs that cover his chest and trail down from his bellybutton in a thin line beneath the waistband of his jeans. Stiles tracks his movements, his breathing becoming more laboured and pre-come pooling on his stomach when Derek reaches his belt buckle.

Derek pulls his belt free and drops it to the floor with a clinking sound. He pops the button of his jeans, pulls down the zipper and pushes aside the flaps to let Stiles see the dark curls that are revealed. He chose to go commando that morning.

"Fuck..." Stiles moans, his eyes fluttering closed for a moment before he regains control and keeps watching.

"Like what you see?" Derek smirks.

"Yeah. Now hurry up." Stiles opens his legs wider. "Need you so bad..."

"Hush. It won't be long now."

True to his word, Derek speeds things up. He pushes his jeans down his powerful thighs, kicks them off and walks to stand in front of Stiles. The omega's eyes are fixed at Derek's groin, where his long, thick alpha cock sticks out straight and proud from the nest of unruly curls at the base. It throbs in time with his heartbeat. The head is hidden in the folds of his foreskin and pre-come drips onto the carpet, more and more each time Derek inhales the sweet scent of his mate's heat. His furry balls are full and heavy between his legs, ready to breed his mate.

The thought startles him for a moment because they hadn't discussed having pups this early, but Derek knows there is little he can do about it now. Like Stiles had said, he needs him.

After allowing Stiles to look his fill, Derek joins the omega on the bed and kneels between his coltish legs. "Just gonna make sure you're ready for me," he says quietly. He pushes one of Stiles' legs further to the side and lifts the other up so that Stiles' foot is next to his ear and his hole is exposed. Derek's eyes turn red as he stares down at the fluttering muscle.

Because they have a very, _very_ active sex life, Derek has seen Stiles in a state of arousal many times before. This is something else.

Stiles has never been this _wet_.

From the state of his underwear, Derek already knew this would be the case, but seeing it right in front of him is indescribable. His mate's poor hole clenches repeatedly around nothing, desperate for a knot to plug it up good and fill him to bursting with his alpha's seed. With each tremor a new wave of slick pours out, causing a substantial stain to form on the sheets that spreads beneath Stiles. Even without touching it, Derek can feel how much heat emanates from the orifice.

Unable to wait any longer, he reaches between Stiles' legs and skates his right index finger over the omega's most intimate place. Immediately it's like Stiles' hole tries to suck him in. He lets it and Derek thinks it's like sliding his finger into warm butter. Stiles' back arches and he tips his head back as Derek's finger pushes smoothly inside.

He can't wait to replace it with his cock.

With a practised movement he curls his finger upward and brushes the pad against the bump of Stiles' prostate. The reaction is instantaneous and explosive.

Stiles whines high in his throat and tenses all over as he experiences his first orgasm of the afternoon. The first of many, Derek is sure. He paints his own torso with thin come that Derek can't resist bending forward and licking up. It's salty and slightly bitter but still delicious. He laps up every drop and savours it as it goes down his throat, even as Stiles bucks beneath him and pushes back on his finger, trying to get more.

"Shh...nearly there," Derek murmurs against Stiles' nipple.

He thrusts his finger in and out a couple of times before adding a second and scissoring them apart. Thanks to his heat, Stiles stretches quickly around him until Derek is able to fit all four of his fingers snugly inside. Slick continues to leak out around the digits, sliding down to his wrist and dripping onto the bedspread.

Once he deems his mate ready, Derek withdraws his fingers and brings them to his mouth. Like he did with Stiles' come, he laps up the clear fluid and moans. It's sweet like honey, but really there's nothing he can compare it to and do it justice. It's a completely unique taste, wholly Stiles, of which he can never get enough.

When his hand is clean again, Derek opens eyes he hadn't realised he had closed and peers back down at Stiles. The omega seems to be getting worse, and Derek feels guilty for making him wait longer than was necessary. No more, he decides.

"Okay, let's get you taken care of," he murmurs to his mate.

He grabs a pillow to place beneath the small of Stiles' back, raising his ass up to the perfect angle to be fucked. Derek pushes Stiles' legs back with one hand and caresses his smooth globes with the other, admiring their beauty, before a plaintive whine from Stiles spurs him on. He crawls over his mate's prone form and fits himself within the cradle of Stiles' thighs, his hard length sliding over Stiles' balls. He presses a chaste kiss to Stiles' sweaty temple.

"You ready?" he asks, just to make sure.

The omega whines again. "Please...hurts." he croaks.

Derek kisses Stiles' face once more and wedges his hand between their bodies to grasp himself. "Okay, I'm gonna push inside now."

With great care, Derek guides the tip of his cock to Stiles' entrance, which sucks him inside just like it did his fingers. Even though he is sure now that Stiles could handle him plunging in with one jarring thrust, Derek enters his mate slowly, inch by torturous inch. It feels just as amazing as he was anticipating. Every time with Stiles feels amazing, but this is on another level. Because of the heat coursing through the omega's body, he is even hotter inside, even wetter.

When Derek is finally fully sheathed inside of his mate, his heavy balls resting over the top of Stiles' ass, Derek lets all of his tension go. He presses his beloved omega down into the mattress with the full weight of his muscular body, letting Stiles get used to him and take comfort from their closeness.

The omega's breaths are shaky, his hands tightly gripping the sheets. Derek knows that the fire in his gut should be dulled now that he is filled, but just that isn't enough to put it out completely. Derek waits to do anything else until his mate grows impatient and begs him to move.

He is all too happy to oblige.

He lifts himself up on his arms again, his hands either side of Stiles' head, and begins slowly moving his hips. Stiles' slick makes it a smooth glide, even as his hole clenches around him, trying to stop him from leaving every time. Derek sets an easy rhythm, thrusting shallowly at first, watching the omega's face to gauge his handling of it. Stiles' face is scrunched up, but Derek can tell it's from pleasure and not pain and speeds up his movements.

Soon, he is snapping his hips and fucking his mate hard, Stiles' slick making an obscene squelching sound. The viscous fluid is soon everywhere. It gets matted in his pubic hair, drips down heavy balls which slap against Stiles' ass with each thrust.

The primal act of breeding his mate has the alpha in Derek howling in satisfaction. He soon loses himself in the act, allowing the human half of him to retreat back into his mind so that the wolf can take over. He hunkers down over Stiles, his forearms wedged beneath Stiles' shoulders, and buries his nose in Stiles' neck, nipping at the pale flesh and marking him up so that no one will be able to question just who he belongs to. By the time he is finished, Stiles' neck is the way it should always be, a constellation of bruises and bite marks.

" _Mine_!" Derek grits out between his fangs.

"Y-yours," comes Stiles' breathy reply, an automatic thing.

The omega's hands release their tight grip on the sheets and move to grip Derek's body, pulling him impossibly closer until there isn't a millimetre of space between them. Derek can feel Stiles' cock trapped between them, rubbing against the contours of his abs. It isn't long until Stiles tenses up again, his sharp fingernails digging into Derek's back and a sudden wetness spreading between them. Derek is smug at the thought of bringing his mate to the height of pleasure again so quickly.

When Stiles has come down from his second orgasm, he removes his nails from Derek's sweat-slicked back and moves them further south. They end up grasping the firm, hairy globes of his ass instead, and he uses what little strength his heat has left him to pull Derek in, forcing that thick cock even deeper inside of his greedy hole. "Please..." Stiles gasps, looking up with bleary gold eyes at Derek's red ones. "Need you...need your knot."

Derek can never deny his mate anything, not even while lost to his wolf.

Already he can feel the bulb of flesh at the base of his shaft expanding rapidly. Soon it will lock them together so that everything he pumps inside of Stiles will be trapped there, will take. The thought of filling Stiles with his pups, of seeing Stiles' belly large and swollen, is what does it. With a final thrust, Derek sinks in as deep as he can, shoving his massive knot past the resistance of Stiles' tight hole. Stiles throws his head back and releases a loud, choked sound, but Derek is too far gone to care if it is made from pleasure or pain.

When he has tied them firmly together, Derek bears his fangs and sinks them into his omega's shoulder, reopening the mating bite he had put there years ago. Blood fills his mouth and he laps it up as he starts coming, his cock spurting jets of thick seed and his hips grinding in circles. Derek stays there for several long minutes, riding out his long orgasm, his eyes half closed in bliss. Eventually it tapers off and stops completely with one last pulse of come, at which point the animal haze disappears from Derek's mind and he comes back to himself.

After extracting his teeth from Stiles' shoulder and giving the bite one final lick to soothe it, Derek rearranges them so that he is sitting upright with his mate in his lap. Stiles sags boneless against him, the intensity of being joined this way in the throes of his heat causing his body to shake. Derek runs his hands up and down the omega's back to comfort him and buries his nose in Stiles' neck, breathing in the scent of their lovemaking.

Their scents are always intertwined nowadays, but there's just something... _more_ when they're like this.

"You okay?" Derek mumbles when Stiles moves, his heat sated for the moment. When Stiles nods jerkily, Derek smiles contentedly. "Rest. I think we're both going to need it."

* * *

It takes a week for Stiles' heat to end, an entire week of nearly non-stop sex.

Not that either of them complained. Several times a day Derek would plug Stiles up with his knot and then, when it went down, he'd lap up the excess come and slick from his loose and sloppy hole. In the short breaks they had in between rounds, they got in quick showers to clean the sweat from their overexerted bodies before eating, rehydrating and going at it all over again.

When Derek wakes up in the middle of the day on what should be Day 8 of Stiles' heat, it's to find Stiles sleeping soundly next to him. He glances at the clock and is surprised to see that several hours have passed since they both fell asleep. Normally no more than an hour will pass before the renewed scent of Stiles' heat would wake him up and they'd go at it again. That he has been allowed to sleep for much longer leads him to suspect that Stiles' heat has run its course. To make sure, he runs the back of his hand over the omega's pale skin, checking the temperature. It isn't hot to the touch anymore, which confirms Derek's suspicions.

A part of him is glad because he is honestly exhausted, but another part is disappointed. He had enjoyed the constant closeness, being wrapped around and inside of each other 24/7.

With a sigh, Derek reaches for his phone on his nightstand and, once it is switched on, texts Stiles' dad to let him know that Stiles' heat is over. He has a bunch of unread messages from his mother and Laura, all asking where he's been, but he ignores them for now. Task done, Derek leaves his mate to keep sleeping and takes a quick shower to rejuvenate himself.

Now that the near-constant stream of _fuck, claim, breed_ is gone, Derek feels the concerns he'd had when it started make their return. If Stiles ends up pregnant, which is highly likely, he doesn't know what to do about it, whether they're ready to be parents. Stiles is still in college, after all, barely in his twenties. As he wraps a towel around his waist, he resolves to talk to Stiles about his concerns when he wakes up.

Back in the bedroom, Derek dresses himself in a purple Henley and a pair of sweatpants and then glances at the bed. He is surprised to see Stiles looking up at him through half-open eyes. "Hey," he says softly, sitting down next to the omega and running fingers through his hair. "You okay?"

Stiles nods. "Yeah," he croaks. "S'it over?"

"Yeah, it is."

"That means I have to get back to normal life now, right?" Stiles pouts. "Great..."

"I'm afraid so," Derek chuckles. "As great as it may sound, we can't really become hermits and spend all day, every day having sex."

"Damn."

Derek allows the smile on his face to fade into something more serious as he moves the conversation forward. "Anyway, there's something that we need to discuss now that we're both thinking clearly."

Stiles pushes himself up onto his elbow. "Oh?"

"Your heat...it happened so suddenly that we didn't really have time to use any form of contraception other than your suppressants, which clearly aren't working anymore," Derek points out, picking nervously at the bedding. "What do you want to do about that?"

"We didn't?" Stiles frowns, thinking. His eyes go impossibly wide when he realises that Derek is right and he looks down at his flat stomach. "Oh shit, we didn't!"

"We have options," Derek says quietly, staring at Stiles' stomach himself. He tries not to imagine what it would look like rounded with his pups and fails miserably. "We could get a morning-after pill or something, or we could wait a bit and then..." The words feel impossibly wrong to speak, but he forces them out. "We could get it taken care of later if you need more time to mull it over."

Stiles is quiet for a long time, so long that Derek becomes antsy. He wonders what his precious omega is thinking but refrains from asking. This is Stiles' decision and Stiles' decision alone, and he has intruded enough.

Eventually, Stiles looks up again. "What do you want to do?"

Derek swallows around the lump in his throat and shakes his head. "This isn't about what I want."

Stiles raises a disbelieving eyebrow. "So this _isn't_ your kid that's potentially growing inside me right now?"

"It's your body, Stiles."

"Yes, I'm the one who'll have to go through everything so this is ultimately up to me, but you still deserve to have some input here," the omega counters, reaching for Derek's hand. He places it on his stomach and holds it there with his own, his eyes never leaving Derek's. "You're telling me that if I went to the drug store right now or to Planned Parenthood in a couple of months that you would have no problem? You're telling me that wouldn't hurt or even destroy you inside? Because if you are, I don't believe you."

"That doesn't matter..." Derek whispers, even as his brain protests.

"Tell me," Stiles insists. "Tell me what you want."

"I—"

"Yes?"

"I— I want it, okay?" Derek sighs. He breaks eye contact, ashamed. "I want it."

Stiles is silent for a moment but then he uses his other hand to cup the alpha's bearded cheek and turn his face back to his own. Derek resists at first but then relents, feeling alarmed when he is met with wet eyes. "I'm sorry," Derek says quickly, thinking he has said the wrong thing and upset his mate.

"No, don't be," Stiles shakes his head, sniffling. He smiles beatifically. "You have no nothing to be sorry for. These are happy tears. I want it, too."

Derek freezes, his confusion melting into hope. "Y-you do?"

Stiles nods. "I do. It's going to be hard. I mean, I've got school full-time and you've got a full-time job and I barely know anything about being a parent, but we'll manage somehow. Nothing would make me happier than to carry your kid, Derek."

"Is this— Are we really doing this?" Derek asks, his voice cracking.

"We are, Der," Stiles grins, kissing him before hugging him fiercely. "We're going to be parents! Well, maybe. I hope we are. If not, then we can just try again next time, right?"

"I love you," Derek whispers into Stiles neck.

"Love you, too, Sourwolf. God, my dad is going to _freak_ ," Stiles giggles.

Derek tenses slightly, nerves creeping in. "Yeah..."

"It's alright, I'll protect you."

Derek huffs. He pulls back and rests their foreheads together. "Thanks."

"You know he'll be on board when he gets over the initial shock. Then we'll be golden. He'll love being a granddad."

"Our kid's going to be spoiled, isn't she?" Derek sighs.

Stiles smiles, amused. "She, huh?"

"Or he. I'll love our pup either way, but yeah, I do kinda want a girl."

"Alright. And as for your question, she sure as shit is going to be _majorly_ spoiled."

"Great."

"How soon until we know for sure? It's too soon to do a test now, right?"

"There's no point. I'll be able to smell it."

Stiles blinks, surprised. "Really?"

Derek shakes his head with fond exasperation. "Didn't you pay attention in biology class?"

The omega flushes red. "Sometimes..."

"Well, being pregnant changes your scent. In a few days," Derek says, brushing his hand over Stiles' bare stomach, "we'll know."

Stiles smiles sweetly. "It's way sooner than I thought it would be, but I really hope I am."

"Me, too."

* * *

Three days later, they find out he is.

**Author's Note:**

> And they lived happily ever after.
> 
> So, I hadn't written smut in months and the urge struck me, so I hope you enjoyed my very first PWP. It's probably nothing spectacularly unique, but I love alpha!Derek/omega!Stiles and just had to write this anyway. I'll probably be writing more smut soon, but on what, I don't know. Suggestions are welcome. Tell me what you want and I shall deliver. ;)
> 
> **P.S. Don't forget to check out my other Sterek works. :)**


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